Platelet recovery after allogeneic haemopoietic stem cell transplant (HSCT) and predictive factors were analysed in 342 patients with haematological malignancies. All patients were prepared with cyclophosphamide plus total body irradiation, and received an unmanipulated HSCT from an HLA‐identical sibling (n = 270), a matched unrelated donor (n = 67) or an identical twin (n = 5). The source of stem cells was peripheral blood (n = 15) or bone marrow (n = 327). Graft‐vs.‐host disease (GvHD) prophylaxis consisted of cyclosporin A with or without methotrexate. The proportion of patients with < 50 × 109/l platelets on d +50, d +100, d +200 and d +365 after HSCT was 26%, 27%, 14% and 11% respectively. Thrombocytopenia was independent of the degree of complete donor chimaerism. Four variables were predictive of platelet recovery: donor type, acute GvHD, cytomegalovirus (CMV) infection and number of cells infused at transplant. Recipients of an unrelated graft had lower platelet counts (49 × 109/l) on d +50 than identical sibling grafts (108 × 109/l) (P < 0·001) and twin grafts (149 × 109/l) (P < 0·001). Patients with GvHD grades 0, I, II, III and IV had significantly different platelet counts on d +50 (153 × 109/l, 102 × 109/l, 85 × 109/l, 32 × 109/l and 22 × 109/l; P < 0·001) and thereafter. Thrombocytopenia was more frequent in patients with high‐level CMV antigenaemia (> four positive cells/2 × 105) (P < 0·0001) and in patients who received a low cell dose at transplant (≤ 4·1 × 108/kg) (P = 0·009). Platelet counts predicted transplant‐related mortality (TRM) and were higher at all time intervals in patients surviving the transplant. Patients with grade II GvHD and > 50 × 109/l platelets had a lower TRM than patients with grade II GvHD and ≤ 50 × 109/l platelets (14% vs. 40%, P < 0·0001). In conclusion, (i) a significant proportion of allogeneic HSCT recipients are thrombocytopenic long‐term, irrespective of complete donor chimaerism, (ii) thrombocytopenia identifies patients at greater risk of lethal complications, and (iii) platelet recovery is influenced by GvHD, donor type, CMV infections and cell dose, not by stem cell source or other patient–disease‐related variables.

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This is a retrospective analysis of 95 patients with myelofibrosis who were allografted between 2001 and 2014. The aims of the study were to assess whether the outcome of alternative donor grafts has improved with time and how this compares with the outcome of identical sibling grafts. Patients were studied in 2 time intervals: 2000 to 2010 (n = 58) and 2011 to 2014 (n = 37). The Dynamic International Prognostic Scoring System score was comparable in the 2 time periods, but differences in the most recent group included older age (58 versus 53 years, P = .004), more family haploidentical donors (54% versus 5%, P < .0001), and the introduction of the thiotepa-fludarabine-busulfan conditioning regimen (70% of patients versus 2%, P < .0001). Acute and chronic graft-versus-host disease were comparable in the 2 time periods. The 3-year transplantation-related mortality (TRM) in the 2011 to 2014 period versus the 2000 to 2010 period is 16% versus 32% (P = .10), the relapse rate 16% versus 40% (P = .06), and actuarial survival 70% versus 39% (P = .08). Improved survival was most pronounced in alternative donor grafts (69% versus 21%, P = .02), compared with matched sibling grafts (72% versus 45%, P = .40). In conclusion, the outcome of allografts in patients with myelofibrosis has improved in recent years because of a reduction of both TRM and relapse. Improvement is most significant in alternative donor transplantations, with modifications in donor type and conditioning regimen.

The role of DNA damage in PCR processivity/fidelity is a relevant topic in molecular investigation of aged/forensic samples. In order to reproduce one of the most common lesions occurring in postmortem tissues, a new protocol based on aqueous hydrolysis of the DNA was developed in vitro. Twenty-five forensic laboratories were then provided with 3.0 μg of a trial sample (TS) exhibiting, in mean, the loss of 1 base of 20, and a molecular weight below 300 bp. Each participating laboratory could freely choose any combination of methods, leading to the quantification and to the definition of the STR profile of the TS, through the documentation of each step of the analytical approaches selected. The results of the TS quantification by qPCR showed significant differences in the amount of DNA recorded by the participating laboratories using different commercial kits. These data show that only DNA quantification "relative" to the used kit (probe) is possible, being the "absolute" amount of DNA inversely related to the length of the target region (r(2) = 0.891). In addition, our results indicate that the absence of a shared stable and certified reference quantitative standard is also likely involved. STR profiling was carried out selecting five different commercial kits and amplifying the TS for a total number of 212 multiplex PCRs, thus representing an interesting overview of the different analytical protocols used by the participating laboratories. Nine laboratories decided to characterize the TS using a single kit, with a number of amplifications varying from 2 to 12, obtaining only partial STR profiles. Most of the participants determined partial or full profiles using a combination of two or more kits, and a number of amplifications varying from 2 to 27. The performance of each laboratory was described in terms of number of correctly characterized loci, dropped-out markers, unreliable genotypes, and incorrect results. The incidence of unreliable and incorrect genotypes was found to be higher for participants carrying out a limited number of amplifications, insufficient to define the correct genotypes from damaged DNA samples such as the TS. Finally, from a dataset containing about 4500 amplicons, the frequency of PCR artifacts (allele dropout, allele drop-in, and allelic imbalance) was calculated for each kit showing that the new chemistry of the kits is not able to overcome the concern of template-related factors. The results of this collaborative exercise emphasize the advantages of using a standardized degraded DNA sample in the definition of which analytical parameters are critical for the outcome of the STR profiles.

Summary:We developed a PCR-based method to monitor clonogenic IgH VDJ rearrangement as a possible predictor of relapse in patients with acute B-ALL after allogeneic bone marrow transplantation (BMT). We studied 23 patients at diagnosis, before and after BMT. At the time of BMT, 13 patients were in first complete remission, eight in second complete remission and two in relapse. Four patients were PCR negative before BMT and remained PCR negative also after BMT (؊/؊ pattern). They are still in remission after a median follow-up of 41 months. Nineteen patients were MRD-positive before BMT: three were PCR negative at first determination after BMT (+/؊ pattern) and maintain remission. Sixteen patients were PCR-positive at first determination after BMT (+/+ pattern): five became PCR negative (+/+/؊ pattern) (four with chronic graft-versus-host disease (GVHD) and two after donor lymphocyte infusions (DLI)). Nine patients remained PCR-positive (+/+/+ pattern) (four remain in remission, and six relapsed); two patients died before transplant. In conclusion, PCR negative patients before BMT remained negative post-BMT; many pre-BMT positive patients had initial MRD positivity after BMT: 37% of them achieved a molecular remission with cGVHD or DLI. significant relapse risk. 4 A lower relapse rate in ALL patients with chronic graft-versus-host disease (cGVHD) has been reported and GVHD was the most significant predictor of relapse in multivariate analysis in a large series of patients.3 This study suggests that the alloimmune response is crucial both to prevent leukemic relapse and to improve survival. Nevertheless donor lymphocyte infusion (DLI) does not exert a significant antileukemic effect in ALL patients relapsing after BMT, 5 differently from patients with CML, where more than 80% of patients relapsing after BMT are responsive to DLI. A possible explanation for this different behavior relies on the fact that in CML patients DLI is performed in early (ie cytogenetic) relapse, possibly when the tumor burden is low. According to this hypothesis, in CML DLI are ineffective in hematologic relapse, especially when it occurs in the accelerated or blastic phase. In CML this has suggested close cytogenetic and molecular monitoring after BMT.